|Publication number||US5365976 A|
|Application number||US 07/884,016|
|Publication date||Nov 22, 1994|
|Filing date||May 18, 1992|
|Priority date||Jun 3, 1991|
|Also published as||CA2043778A1, CA2043778C|
|Publication number||07884016, 884016, US 5365976 A, US 5365976A, US-A-5365976, US5365976 A, US5365976A|
|Original Assignee||Peter Tozer|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (13), Referenced by (6), Classifications (5), Legal Events (5)|
|External Links: USPTO, USPTO Assignment, Espacenet|
The present invention relates to the field of methods and apparatus for stopping the flow of fluids under pressure from conduits. The present invention is particularly applicable to stopping the uncontrolled escape of natural gas from pressure lines.
It is often necessary, when servicing natural gas lines or responding to emergencies in residential, commercial or industrial environments, to stop the flow of gas from a pressurized line in a situation where no valve is accessible, or the only accessible valve is broken or cannot be used because shutting it would adversely affect gas flow in an adjacent line. Techniques have been developed, therefore, to stop gas flow from an open pipe.
The simplest method of stopping the flow of gas from a pressurized line is to insert a wooden plug in the open end of the pipe, and then apply strong adhesive tape, such as POLYKEN.sup.™ tape to the pipe and the plug to hold the plug in the pipe. The disadvantages of this technique are obvious, however. It is difficult to insert a plug into a line against a strong flow of gas; the wood has a tendency to split when being inserted or driven into the line; and even though strong adhesive tape is used, the plug may pop out with dangerous effect. Also, this method is time consuming, and it is desirable to stop an uncontrollable gas flow as quickly as possible, because of the poisonous and explosive nature of natural gas.
A slightly more advanced method of stopping gas flow is by insertion of a device known as a MUELLER EXPANDO STOPPER.sup.™. This device is a threaded rod having at one end a nut threaded thereon, a wide deformable rubber washer above the nut, the rubber washer being bracketed, top and bottom by metal washers, a sleeve above the rubber washer, and a wing nut threaded on the rod above the sleeve. The end of the rod above the wing nut is bent to form a handle. To stop a flow of gas using this device, it is inserted by hand into the gas line against the flow of pressurized gas, and held in place while the wing nut is tightened. Tightening the wing nut causes the sleeve below it to press down against the deformable rubber washer, which bulges outwardly, filling the space between it and the pipe, thereby stopping the flow of gas. Once tightened in this way, it, like a wooden plug is held in place with strong adhesive tape. The problem with this device is that it is difficult to insert into a pipe by hand, and difficult to hold in place for tightening of the wing nut, making installation of it a two person operation. Also, because outward flow of gas on the metal washer at the bottom of the rubber washer acts in a manner similar to the tightening of the wing nut, the rubber washer has a tendency, when being used in high pressure situations, to expand when being inserted, thereby foiling the efforts of service personnel.
In the event that neither of the aforementioned techniques proves effective, service personnel usually resort to squeezing off, the flow of gas by means of a hydraulic jack operated crimping tool such as a REGENT JACK. This is a time consuming operation usually taking more than half an hour, and destroys a portion of pipe,.which must thereafter be replaced.
The object of the present invention is to provide a tool that is easy to use under virtually any conditions to stop the flow of gas from a pressure line quickly and efficiently.
In a broad aspect, the present invention relates to a device for stopping the flow of fluid under pressure from an open-ended pipe including: (i) clamp means adapted to grasp said pipe adjacent its open end; (ii) stopper holder means extending from said clamp means and being alignable with the open end of said pipe; and (iii) stopper means adapted to be held by said stopper holder means in a position aligned with the open end of said pipe and insertable from said aligned position into said pipe to stop the flow of fluid from said pipe.
In drawings that illustrate the present invention by way of example:
FIG. 1 is a perspective view, partially in phantom, of the clamp means of the present invention;
FIG. 2 is a front view of the device of FIG. 1;
FIG. 3 is a side view of the device of FIG. 1;
FIG. 4 is a top view of the device of FIG. 1; and
FIG. 5 is a side view of the stopper of the present invention, for use in association with the clamp means of FIG. 1.
Referring to FIGS. 1 to 4, the present invention provides a tool including a clamp 1 having angulated jaws 2 to grasp a pipe such as a residential natural gas pipe. As illustrated, clamp 1 is shown as a Vise-Grip.sup.™ clamping pliers, but any suitable clamp, such as a standard C-clamp will be usable in the present invention with acceptable results. A post 3 extends generally parallel to the jaws 2 of the clamp, outwardly from one end of the clamp 1.
A stopper holder 4 is swivelly mounted on post 3 by upper and lower hinges 12, 11. Holder 4 is provided with a skirt 5 at its lowermost edge. Skirt 5 will contact the upper surface of a pipe when clamp jaws 2 are fastened thereon, and stopper holder 4 is rotated into position over the open end of the pipe. When skirt 5 contacts a pipe, the stopper (described below) will be axially aligned with the pipe.
The upper end of post 3 is threaded, and a threaded bolt 10 engages it. When holder 4 is swung into place over an open pipe, bolt 10 may then be tightened against the upper hinge 12 of holder 4 to prevent it from swivelling out of alignment with the open end of the pipe. Bolt 10 may be provided with a handle member 9, for ease of turning by a gloved repair person. If so, because it will only be possible to turn bolt 10 less than a full revolution, it is tightened almost fully against the hinge in its normal state, so that tightening fully requires only a short push of handle 9. Other quick-tightening methods for quickly securing alignment of holder 4 over the open end of the pipe will be obvious to one skilled in the art.
Holder 4 is provided with an axial bore extending its entire length. The bore is of greater diameter at the lower end of the holder, and narrows at the upper end thereof, to permit the stopper to be held in the holder against a strong flow of gas. A wide slot 23 extends the length of the holder to permit the insertion of the stopper into the holder. A second, narrow, slot 8, on the opposite side of the holder permits the passage of stopper retaining fluke 13 half-way down the bore thereof. Narrow slot 8 and wide slot 23 each have an arcuate slot 6 extending away therefrom, terminating in a short, upwardly extending retaining slot 7.
Referring to FIG. 5, stopper 7 comprises a central threaded rod 17, having a bullet shaped bolt 21 threaded onto the lower end thereof. To prevent accidental loosening of bullet-shaped bolt 21 from the end of rod 17, the threads of rod 17 are preferably treated with a thread dope before bolt 21 is threaded onto same. The upper end of bolt 21 is recessed to form an indented seating 22 to admit the lowermost end of an expanding, deformable rubber washer 20 located just above same. Above expanding washer 20 is a steel flat washer 19, so that downward pressure on flat washer 19 will cause expanding washer 20 to be squeezed and expand. Above flat washer 19 is lower sleeve 18, and above lower sleeve 18 a collar 24 from which extend stopper retaining flukes 13. Collar 24 may be integral with sleeve 18, or it may be separate therefrom. Conveniently, collar 24 may be an inverted wing nut, with the wings serving as retaining flukes 13. It is not necessary, however, that collar 24 be threaded onto rod 17. Upper sleeve 15 extends upwardly from collar 24 a distance at least equal to and preferably greater than the distance between the upper end of holder 4 and the upper edges of arcuate slots 6, so as to permit the rotation of flukes 13 in arcuate slots 6. It will be observed that upper sleeve 15, collar 24 (with flukes 13) and lower sleeve 18 may be formed as a single unit if desired.
Above upper sleeve 15 is located nut 14 threaded onto rod 17. Nut 14 is preferably a wing nut to facilitate its being turned by a gloved worker. Rod 17 is bent above nut 14, to provide a handle 16 that may be grasped when nut 14 is turned.
The device of the present invention is used as follows to stop the flow of gas from a pipe:
i) Jaws 2 are fastened onto a pipe near the open end thereof. At this time, the stopper holder 4 will be swung away from the jaws 2, so as not to be blown by the escaping gas.
ii) The stopper is inserted into the stopper holder by slipping lower 18 sleeve through longitudinal slot 23. The stopper is then pulled up into the holder, so that the holder can be swivelled over the open end of the pipe. When the stopper is pulled up into the holder 4, flat washer 19 will contact the upper narrow part of the central bore of the holder 4;
iii) Holder 4 is then swivelled into place over the end of the pipe, so that skirt 5 contacts the side of the pipe. The stopper is then axially aligned with the pipe, and bolt 10 may be turned by handle 9 to secure the stopper holder 4 in place.
iv) The stopper is then pushed into the pipe by pushing on handle 16. The bullet-shape of the end of the stopper facilitates pushing it in against the flow of gas, and the recessed seating of expanding washer 20 in bullet shaped nut 21 prevents gas pressure from deforming expanding washer 20 by pressing on it from below.
v) As the stopper is manually pushed into, the gas line, care is taken to align flukes 13 so that they pass half way down the length of the holder via slots 8,23. At the bottom of the slots 8,23, which is detectable by the worker because a fluke 13 will impact the bottom of slot 8, flukes 13 are then manually rotated through arcuate slots 6, at which point the worker eases manual pressure on handle 16, thereby permitting flukes 13 to travel up retaining slots 7 (being pushed up by pressure on bullet-shaped nut 21) and secure the stopper in the holder, with expanding washer 20 being located in the pipe.
vi) The worker then firmly grasps handle 16 to prevent rod 17 from rotating, and tightens wing nut 14, causing sleeve 18 to bear on flat washer 19, which squeezes expanding washer 20 against bullet shaped nut 21. The expansion of expanding washer 20 stops the flow of gas from the pipe, and the operation is complete.
It has been observed in tests that from start to finish, steps (i)-(vi) detailed above may be performed within 10-15 seconds, by a single individual.
It is to be understood that the examples described above are not meant to limit the scope of the present invention. It is expected that numerous variants will be obvious to the person skilled in the tool making field, without any departure from the spirit of the present invention. The appended claims, properly construed, form the only limitation upon the scope of the present invention.
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|U.S. Classification||138/89, 138/94|
|May 20, 1998||FPAY||Fee payment|
Year of fee payment: 4
|Jan 3, 2002||FPAY||Fee payment|
Year of fee payment: 8
|Jun 7, 2006||REMI||Maintenance fee reminder mailed|
|Nov 22, 2006||LAPS||Lapse for failure to pay maintenance fees|
|Jan 16, 2007||FP||Expired due to failure to pay maintenance fee|
Effective date: 20061122